At 11:23 PM 2/13/2001 +0100, guido.klapperich@... wrote:

>Let me see, if I understood it right:
>You say, the OIT is the oldest transaction that rolled-back
>What happens, if I commit every transaction ? Will then OIT be nil ?

If you commit every transaction, the OIT will be the oldest active,
and will move forward as older transactions commit.

>The OH says: If a transaction is left in an active (unresolved) state, this
>is an "interesting" transaction.
>In a given database's transaction inventory, the first transaction with a
>state other than
>committed is known as the Oldest Interesting Transaction (OIT).
>So there are three states left, which the OIT could have: Active, Rolled
>Back and Limbo.

Right. Actives decay into RolledBack (aka Dead), but the OIT could
be any of those three. They're called interesting transactions because
they could have made changes that the active transactions should undo.
Anything that's committed is reliable. Data created by an interesting
transaction is not. So active transactions need to be able to identify
interesting transactions.



Ann
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